289 lines
10 KiB
C++
289 lines
10 KiB
C++
/* @file lambda_xs.cpp */
|
|
|
|
#include "lambda_xs.hpp"
|
|
#include "define_xs.hpp"
|
|
#include "parserstatemachine.hpp"
|
|
#include "exprstatestack.hpp"
|
|
#include "expect_formal_arglist_xs.hpp"
|
|
#include "expect_expr_xs.hpp"
|
|
#include "expect_type_xs.hpp"
|
|
#include "pretty_expression.hpp"
|
|
#include "pretty_variable.hpp"
|
|
#include "xo/expression/Lambda.hpp"
|
|
|
|
namespace xo {
|
|
using xo::scm::Lambda;
|
|
using xo::scm::LocalEnv;
|
|
|
|
namespace scm {
|
|
const char *
|
|
lambdastatetype_descr(lambdastatetype x) {
|
|
switch(x) {
|
|
case lambdastatetype::invalid: return "invalid";
|
|
case lambdastatetype::lm_0: return "lm_0";
|
|
case lambdastatetype::lm_1: return "lm_1";
|
|
case lambdastatetype::lm_2: return "lm_2";
|
|
case lambdastatetype::lm_3: return "lm_3";
|
|
case lambdastatetype::lm_4: return "lm_4";
|
|
case lambdastatetype::lm_5: return "lm_5";
|
|
default: break;
|
|
}
|
|
|
|
return "???lambdastatetype";
|
|
}
|
|
|
|
// ----- lambda_xs - ----
|
|
|
|
std::unique_ptr<lambda_xs>
|
|
lambda_xs::make() {
|
|
return std::make_unique<lambda_xs>(lambda_xs());
|
|
}
|
|
|
|
void
|
|
lambda_xs::start(parserstatemachine * p_psm)
|
|
{
|
|
p_psm->push_exprstate(lambda_xs::make());
|
|
p_psm->top_exprstate()
|
|
.on_lambda_token(token_type::lambda(), p_psm);
|
|
}
|
|
|
|
lambda_xs::lambda_xs() : exprstate(exprstatetype::lambdaexpr) {}
|
|
|
|
const char *
|
|
lambda_xs::get_expect_str() const
|
|
{
|
|
/*
|
|
* lambda (x : f64) : f64 { ... } ;
|
|
* ^ ^ ^ ^ ^ ^
|
|
* | | | | | lm_5
|
|
* | | | | lm_4:expect_expression
|
|
* | | | lm_3
|
|
* | | lm_2
|
|
* | lm_1:
|
|
* expect_expression
|
|
*/
|
|
switch (this->lmxs_type_) {
|
|
case lambdastatetype::invalid:
|
|
case lambdastatetype::lm_0:
|
|
case lambdastatetype::n_lambdastatetype:
|
|
assert(false); // impossible
|
|
return nullptr;
|
|
case lambdastatetype::lm_1:
|
|
return "lambda-params";
|
|
case lambdastatetype::lm_2:
|
|
return "colon|lambda-body";
|
|
case lambdastatetype::lm_3:
|
|
return "type";
|
|
case lambdastatetype::lm_4:
|
|
return "lambda-body";
|
|
case lambdastatetype::lm_5:
|
|
return "semicolon";
|
|
}
|
|
|
|
return "?expect";
|
|
}
|
|
|
|
void
|
|
lambda_xs::on_lambda_token(const token_type & tk,
|
|
parserstatemachine * p_psm)
|
|
{
|
|
if (lmxs_type_ == lambdastatetype::lm_0) {
|
|
this->lmxs_type_ = lambdastatetype::lm_1;
|
|
expect_formal_arglist_xs::start(p_psm);
|
|
} else {
|
|
exprstate::on_lambda_token(tk, p_psm);
|
|
}
|
|
}
|
|
|
|
void
|
|
lambda_xs::on_formal_arglist(const std::vector<rp<Variable>> & argl,
|
|
parserstatemachine * p_psm)
|
|
{
|
|
if (lmxs_type_ == lambdastatetype::lm_1) {
|
|
this->lmxs_type_ = lambdastatetype::lm_2;
|
|
this->parent_env_ = p_psm->top_envframe().promote();
|
|
this->local_env_ = LocalEnv::make(argl, parent_env_);
|
|
|
|
p_psm->push_envframe(local_env_);
|
|
|
|
//expect_expr_xs::start(p_psm);
|
|
} else {
|
|
exprstate::on_formal_arglist(argl, p_psm);
|
|
}
|
|
}
|
|
|
|
void
|
|
lambda_xs::on_expr_with_semicolon(bp<Expression> expr,
|
|
parserstatemachine * p_psm)
|
|
{
|
|
this->on_expr(expr, p_psm);
|
|
this->on_semicolon_token(token_type::semicolon(), p_psm);
|
|
}
|
|
|
|
void
|
|
lambda_xs::on_colon_token(const token_type & tk,
|
|
parserstatemachine * p_psm)
|
|
{
|
|
constexpr const char * c_self_name = "lambda_xs::on_colon_token";
|
|
|
|
if (lmxs_type_ == lambdastatetype::lm_2) {
|
|
this->lmxs_type_ = lambdastatetype::lm_3;
|
|
expect_type_xs::start(p_psm);
|
|
/* control reenters via .on_typedescr() */
|
|
} else {
|
|
this->illegal_input_on_token(c_self_name, tk, this->get_expect_str(), p_psm);
|
|
}
|
|
}
|
|
|
|
void
|
|
lambda_xs::on_leftbrace_token(const token_type & tk,
|
|
parserstatemachine * p_psm)
|
|
{
|
|
constexpr const char * c_self_name = "lambda_xs::on_leftbrace_token";
|
|
|
|
if (lmxs_type_ == lambdastatetype::lm_2)
|
|
this->lmxs_type_ = lambdastatetype::lm_4;
|
|
|
|
if (lmxs_type_ == lambdastatetype::lm_4) {
|
|
expect_expr_xs::start(p_psm);
|
|
/* want { to start expr sequence, that finishes on matching } */
|
|
p_psm->on_leftbrace_token(token_type::leftbrace());
|
|
} else {
|
|
this->illegal_input_on_token(c_self_name, tk, this->get_expect_str(), p_psm);
|
|
}
|
|
}
|
|
|
|
void
|
|
lambda_xs::on_typedescr(TypeDescr td,
|
|
parserstatemachine * p_psm)
|
|
{
|
|
constexpr const char * c_self_name = "lambda_xs::on_typedescr";
|
|
scope log(XO_DEBUG(p_psm->debug_flag()));
|
|
|
|
assert(td);
|
|
|
|
if (lmxs_type_ == lambdastatetype::lm_3) {
|
|
this->lmxs_type_ = lambdastatetype::lm_4;
|
|
this->explicit_return_td_ = td;
|
|
|
|
this->lambda_td_ = Lambda::assemble_lambda_td(local_env_->argv(),
|
|
explicit_return_td_);
|
|
|
|
/* 1. at this point we know function signature (@ref lambda_td_)
|
|
* 2. if this lambda appears on the rhs of a define,
|
|
* propagate function signature to the define.
|
|
* 3. this makes recursive function definitions like this work
|
|
* without relying on type inference:
|
|
* def fact = lambda (n : i64) : i64 {
|
|
* if (n == 0) then
|
|
* 1
|
|
* else
|
|
* n * fact(n - 1)
|
|
* }
|
|
* 4. while parsing the body of the lambda, we want environment
|
|
* to already associate the lambda's signature with variable 'fact',
|
|
* so that when parser encounters 'fact(n - 1)' the expression has
|
|
* known valuetype.
|
|
*/
|
|
|
|
if ((p_psm->exprstate_stack_size() >= 3)
|
|
&& (p_psm->lookup_exprstate(1).exs_type() == exprstatetype::expect_rhs_expression)
|
|
&& (p_psm->lookup_exprstate(2).exs_type() == exprstatetype::defexpr)
|
|
&& (p_psm->env_stack_size() >= 2)
|
|
)
|
|
{
|
|
const define_xs * def_xs = dynamic_cast<const define_xs*>(&(p_psm->lookup_exprstate(2)));
|
|
|
|
assert(def_xs);
|
|
|
|
bp<Variable> def_var = def_xs->lhs_variable();
|
|
|
|
if (def_var->valuetype() == nullptr) {
|
|
log && log("assign discovered lambda type T to enclosing define",
|
|
xtag("lhs", def_var.get()),
|
|
xtag("T", print::unq(this->lambda_td_->canonical_name())));
|
|
|
|
def_var->assign_valuetype(lambda_td_);
|
|
} else {
|
|
/* don't need to unify here. if def already hasa a type,
|
|
* that's because it was explicitly specified.
|
|
* will discover any conflict after reporting parsed lambda
|
|
* to define_xs
|
|
*/
|
|
}
|
|
}
|
|
|
|
expect_expr_xs::start(p_psm);
|
|
/* control reenters via .on_expr() or .on_expr_with_semicolon() */
|
|
} else {
|
|
this->illegal_input_on_type(c_self_name, td, this->get_expect_str(), p_psm);
|
|
}
|
|
}
|
|
|
|
void
|
|
lambda_xs::on_expr(bp<Expression> expr,
|
|
parserstatemachine * p_psm)
|
|
{
|
|
constexpr const char * c_self_name = "lambda_xs::on_expr";
|
|
|
|
if (lmxs_type_ == lambdastatetype::lm_4) {
|
|
this->lmxs_type_ = lambdastatetype::lm_5;
|
|
this->body_ = expr.promote();
|
|
} else {
|
|
this->illegal_input_on_expr(c_self_name, expr, this->get_expect_str(), p_psm);
|
|
}
|
|
}
|
|
|
|
void
|
|
lambda_xs::on_semicolon_token(const token_type & tk,
|
|
parserstatemachine * p_psm)
|
|
{
|
|
if (lmxs_type_ == lambdastatetype::lm_5) {
|
|
/* done! */
|
|
|
|
std::unique_ptr<exprstate> self = p_psm->pop_exprstate();
|
|
|
|
std::string name = Variable::gensym("lambda");
|
|
|
|
/* top env frame recorded arguments to this lambda */
|
|
p_psm->pop_envframe();
|
|
|
|
rp<Lambda> lm;
|
|
|
|
/* TODO: unify explicit_return_td_ with body_ */
|
|
|
|
if (lambda_td_) {
|
|
lm = Lambda::make(name, lambda_td_, local_env_, body_);
|
|
} else {
|
|
lm = Lambda::make_from_env(name, local_env_,
|
|
explicit_return_td_, body_);
|
|
}
|
|
|
|
p_psm->top_exprstate().on_expr(lm, p_psm);
|
|
p_psm->top_exprstate().on_semicolon_token(tk, p_psm);
|
|
|
|
return;
|
|
}
|
|
|
|
exprstate::on_semicolon_token(tk, p_psm);
|
|
}
|
|
|
|
void
|
|
lambda_xs::print(std::ostream & os) const {
|
|
os << "<lambda_xs"
|
|
<< xtag("lmxs_type", lmxs_type_)
|
|
<< ">";
|
|
}
|
|
|
|
bool
|
|
lambda_xs::pretty_print(const xo::print::ppindentinfo & ppii) const
|
|
{
|
|
return ppii.pps()->pretty_struct(ppii, "lambda_xs",
|
|
refrtag("lmxs_type", lmxs_type_));
|
|
}
|
|
|
|
} /*namespace scm*/
|
|
} /*namespace xo*/
|
|
|
|
|
|
/* end lambda_xs.cpp */
|